Cumulative Trauma and Adjustment in Women Exposed to a Campus Shooting: Examining the Role of Appraisals and Social Support

Abstract

Experiencing repeated trauma can have increasingly detrimental effects on psychosocial functioning after subsequent stressors. These effects may be intensified for victims of interpersonal traumas given that these events are often associated with heightened risk for adverse outcomes. To better understand this relationship, the present study prospectively examined the effect of pre-shooting trauma exposure (i.e., interpersonal vs. non-interpersonal trauma) on psychological functioning (i.e., posttraumatic stress symptoms, depression) following a mass campus shooting. Based on previous research, it was expected that negative appraisals and social support would mediate this relationship. A sample of 515 college women reporting prior trauma exposure was assessed at four time points following the shooting (i.e., pre-shooting, 1-month, 6-months, and 12-months post-shooting). Bootstrap analyses with bias-corrected confidence intervals were conducted. Contrary to expectation, pre-shooting trauma exposure was unrelated to 12-month post-shooting outcomes and neither negative appraisals nor social support at 6-months post-shooting emerged as mediators. Interestingly, a history of non-interpersonal trauma was associated with greater post-shooting family and friend support than a history of interpersonal trauma. Ad hoc analyses showed that pre-shooting symptom severity and level of exposure to the shooting had indirect effects on post-shooting outcomes via post-shooting negative appraisals. These findings support that cumulative trauma, regardless of type, may not have an additive effect unless individuals develop clinically significant symptoms following previous trauma. Trauma severity also appears to play a meaningful role.

Keywords

cumulative trauma negative appraisals campus shooting PTSD depression

A growing body of literature suggests that experiencing multiple traumatic events has greater adverse effects on subsequent functioning than exposure to a single event, including elevated symptoms of posttraumatic stress disorder (PTSD) and depression (Breslau, Chilcoat, Kessler, & Davis, 1999; Briere, Kaltman, & Green, 2008; Cloitre et al., 2009; Cougle, Resnick, & Kilpatrick, 2009; Frans, Rimmö, Åberg, & Fredrison, 2005; Kimerling, Alvarez, Pavao, Kaminski, & Baumrind, 2007; Krupnick et al., 2004; Littleton, Grills-Taquechel, Axsom, Bye, & Buck, 2012; Nishith, Mechanic, & Resick, 2000). It has been proposed that prior trauma exposure intensifies responses to subsequent stressors, even relatively minor events (i.e., sensitization effect; Hammen, Henry, & Daley, 2000). Alternatively, later exposure to more severe traumas may enhance conditioned responses to previous stressful events of moderate intensity (i.e., inflation effect; Rescorla, 1974). There is limited research and support for the inflation effect in relation to PTSD (Rau, DeCola, & Fanselow, 2005). By contrast, numerous studies have found a sensitization effect for PTSD (e.g., Breslau et al., 1999; Brewin, Andrews, & Valentine, 2000; McLaughlin, Conron, Koenen, & Gilman, 2010). The explanatory power of the sensitization hypothesis may be enhanced by delineating the mechanisms underlying the effects of cumulative trauma exposure, such as negative appraisals and social support (Littleton et al., 2012).

Traumatic events often violate global beliefs about people and the world as benevolent, the self as valuable, and the world as just (Park, Mills, & Edmondson, 2012). As a result, individuals’ assumptions about themselves and the world are threatened in a way that contributes to elevated distress (Ehlers & Clark, 2000; Resick & Schnicke, 1992). Attempts to resolve the discrepancy between these new assumptions and global beliefs may lead to the development of extreme negative beliefs (Resick & Schnicke, 1992). There is robust evidence implicating negative appraisals in the etiology and chronicity of PTSD (e.g., Bryant & Guthrie, 2007; Bryant, Salmon, Sinclair, & Davidson, 2007; Dunmore, Clark, & Ehlers, 2001; Ehlers, Maercker, & Boos, 2000; Karl, Rabe, Zöllner, Maercker, & Stopa, 2009; O’Donnell, Elliott, Wolfgang, & Creamer, 2007), thus, illustrating its potentially sensitizing effect on pathological responses to new trauma exposure. Repeated trauma exposure likely strengthens these negative appraisals and makes them more resistant to change (Cason, Resick, & Weaver, 2002). In addition, exposure to multiple traumatic experiences may cause individuals to re-evaluate the danger posed by previous traumas leading to the reinstatement of PTSD symptoms associated with those initial traumas (Mineka & Zinbarg, 2006).

Social support can serve as a buffer against negative appraisals and post-trauma sequelae (Schumm, Briggs-Phillips, & Hobfoll, 2006). Support networks promote adaptive coping through processes such as modeling and provide a sense of security that enhances overall well-being and perceived self-worth (Littleton, 2010). Unfortunately, repeated trauma exposure can adversely affect social support networks due to individuals becoming more withdrawn or demonstrating greater impairment in their ability to have meaningful relationships (Guay, Billette, & Marchand, 2006; King, King, Taft, Hammond, & Stone, 2006). Victims of repeated interpersonal trauma may also have difficulties trusting others and question others’ intentions leading to an avoidance of relationships and poor social problem-solving behaviors (Littleton et al., 2012). For these reasons, a persistent lack of social support could heighten the intensity of adverse reactions to repeated traumatic experiences.

To date, only one study has investigated the impact of negative appraisals and social support in relation to cumulative trauma (Littleton et al., 2012). Littleton et al. examined the mediating role of negative appraisals and social support on the adjustment of 215 women with and without a history of sexual violence following the Virginia Tech campus shooting. Consistent with the sensitization hypothesis, they observed significant direct effects of victimization status (i.e., survivors of sexual violence vs. non-victims) on post-shooting symptoms of PTSD and depression. They also found significant indirect effects showing that more negative benevolence beliefs (e.g., “The world is a good place”) and less family support among victims of sexual violence (as compared with women without a history of sexual violence; that is, non-victims) were associated with poorer post-shooting adjustment. These findings suggest that the nature of subsequent traumas may reinforce certain types of negative beliefs following later trauma. For example, exposure to a mass campus shooting resulted in greater negative beliefs about the world as a dangerous, unpredictable place. For the 8.4% of their sample reporting a history of sexual revictimization, repeated exposure to sexual violence may have strengthened their self-blame and beliefs about themselves as incompetent or damaged (Spaccarelli, 1994). Sexual trauma victims, especially survivors of childhood sexual abuse (CSA), might report less family support given that CSA often occurs within the context of family dysfunction (Finkelhor, 1994; Messman-Moore & Brown, 2004). It is worth noting that the non-victim comparison group was not assessed for a history of other potentially traumatic events. Thus, it is difficult to discern whether it was the accumulation of trauma or if it was the experience of sexual assault that uniquely resulted in worst post-shooting adjustment, although prior interpersonal trauma, in general, appears to be a risk factor for subsequent PTSD (Breslau et al., 1999; Cougle et al., 2009).

Several studies have shown that interpersonal traumas are often associated with a higher conditional risk for PTSD as compared with non-interpersonal traumas (Breslau et al., 1999; Ford, Stockton, Kaltman, & Green, 2006; Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995; Martin, Cromer, DePrince, & Freyd, 2013). Cougle et al. (2009) also found a link between a history of interpersonal trauma and elevated risk for PTSD following new trauma exposure. As Martin et al. (2013) explained, the degree to which trauma victims feel that their trust has been violated as a result of a traumatic experience has a considerable impact on subsequent reactions. They found that interpersonal traumas in which a loved one had betrayed the trust of the victim (i.e., high betrayal traumas) contributed to stronger negative appraisals than non-interpersonal trauma (i.e., low betrayal traumas) regardless of gender. They suggest that survivors of high betrayal traumas may be more prone to developing negative appraisals to maintain a relationship with the perpetrator. This may be particularly true for victims of childhood and adolescent abuse that occurs within a familial context. Violations of trust may also manifest in persistent interpersonal problems as victims of interpersonal trauma may avoid relationships with others due to a lack of trust and fear of future victimization (Littleton et al., 2012). Another important element to consider is the developmental period during which the trauma occurs. Children have fewer cognitive resources, affective regulatory skills, and verbal capacity to effectively process the abuse than adolescents and adults (Meiser-Stedman, 2002). A lack of knowledge regarding the potentially traumatic nature of the abuse may also lead to misinterpretations of the experience (Steward, O’Connor, Acredolo, & Steward, 1996). Finally, it would be less socially acceptable and more emotionally distressing for youth to talk about interpersonal traumatic experiences (e.g., abuse) as compared with non-interpersonal experiences (e.g., natural disaster, violent death of loved one). Consequently, victims of interpersonal trauma are deprived of opportunities to receive corrective feedback that might mitigate the effects of new traumatic experiences.

The present study sought to replicate and extend Littleton et al.’s (2012) findings by examining the effect of pre-shooting trauma exposure (i.e., interpersonal trauma vs. non-interpersonal trauma) on the adjustment of women exposed to a mass campus shooting on February 14, 2008 at Northern Illinois University (NIU). Although there would be great value in testing the sensitization hypothesis within a unique dataset such as this, only 30 (of 638) participants denied any pre-shooting trauma exposure. Furthermore, we noted earlier that it would be difficult to draw inferences about the cumulative effects of different trauma types if non-victims were combined with victims of non-interpersonal trauma. For these reasons, the present study excluded non-victims and focused on differentiating between the cumulative effects of these two classes of trauma exposure. It was hypothesized that differences in post-shooting negative appraisals and social support would mediate the relationship between pre-shooting trauma exposure and post-shooting psychological adjustment (i.e., PTSD and depressive symptoms). Figure 1 shows a graphical depiction of study hypotheses.

Figure 1.

Hypothesized mediational model of direct and indirect relationship between pre-shooting trauma exposure (interpersonal trauma = 1 vs. non-interpersonal trauma = 2) and 12-month outcomes among women exposed to a campus shooting.

Method

Participants and Procedure

Data were obtained from a subsample of 608 college women who completed four waves of a longitudinal study on sexual revictimization. Inclusion criteria were female, at least 18 years old, and fluent in English. A history of sexual victimization was not a prerequisite in the larger study. An additional inclusion criterion for the present study was exposure to at least one Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association [APA], 1994) Criterion A traumatic event. A qualifying Criterion A traumatic event was conceptualized as experiencing, witnessing, or confronting an event(s) that involved actual or threatened death, serious injury, or bodily harm that resulted in a response of intense fear, helplessness, or horror (APA, 2000). Three participants were removed due to missing data across all variables of interest. Of the remaining 605 participants, 526 endorsed a qualifying traumatic event. The final sample consisted of 515 women after removing 11 extreme outliers (±3 SDs) on age (Tabachnick & Fidell, 2007). The mean pre-shooting age was 18.73 years (SD = 1.18 years). The sample self-identified as White (69.3%), followed by Black (19.4%), Asian or South Asian (3.5%), and other/multiracial (7.8%). Ninety-three percent self-identified as non-Hispanic. Most participants were freshmen (74.1%) or sophomores (17.3%).

Data were first collected between August 2006 and February 2008 (T1). At T1, 1,045 participants (885 of whom consented to follow-up contact) completed a 90-min computerized survey during an individual laboratory session for course credit. Within a month of the shooting (T2), 691 (of 812) participants determined to be current NIU students completed an online survey for which they were given the option to receive US$40 or course credit. Participants were compensated US$40 for completing additional online surveys at 6-months (T3; n = 633) and 12-months (T4; n = 617) post-shooting. Prior to each survey, informed consent was obtained. Study procedures were approved by NIU’s institutional review board.

Measures

Pre-shooting trauma exposure

At T1, participants indicated the frequency of exposure and whether they experienced fear, helplessness, or horror to 22 potentially traumatic events, as assessed by the Traumatic Life Events Questionnaire (TLEQ; Kubany, Haynes, et al., 2000). Participants were divided into those with prior interpersonal trauma (coded as 1; n = 334) versus those with prior non-interpersonal trauma (coded as 2; n = 181). Interpersonal traumas were defined as events involving an identifiable perpetrator (i.e., robbery, sexual and/or physical assault, threatened with serious bodily harm, childhood physical and/or sexual abuse, intimate partner violence, being stalked, witnessing physical assault or family violence, combat). Non-interpersonal traumas included events, such as natural disaster, serious motor vehicle or other accident, sudden death of a loved one(s), surviving a life-threatening illness or having a loved one(s) survive a life-threatening illness, abortion, or miscarriage. Participants endorsing both types of trauma were categorized as interpersonal trauma for the reasons listed above.

Shooting exposure severity

Participants’ proximity to the classroom where the shooting occurred (e.g., in the classroom, on campus, not on campus) was measured by 12 yes/no items adapted from Littleton, Axsom, and Grills-Taquechel (2009) at T2. A shooting exposure count score was computed with higher values reflecting more exposure. A high percentage of participants were on campus at the time of the shooting (76.1%), saw police or other personnel surrounding the buildings (69.3%), were in a building placed on lockdown (49.5%), knew someone wounded (34.8%), and/or saw someone hurt or wounded (22.5%).

Post-shooting appraisals

Negative post-shooting appraisals were assessed at T3 using the Posttraumatic Cognition Inventory (PTCI; Foa, Ehlers, Clark, Tolin, & Orsillo, 1999). The PTCI does not include a benevolence subscale; however, its subscales are correlated with other Benevolence scales (rs ≥ |.21|; Foa et al., 1999). Participants rated (1 = totally disagree to 7 = totally agree) the extent to which they had negative beliefs about themselves and the world. (The Self-Blame subscale was omitted due to the random “blameless” nature of the trauma.) The PTCI and its subscales have demonstrated adequate internal consistency as well as good validity (Foa et al., 1999). A mean subscale score was computed for negative self-appraisals and negative world-appraisals with each subscale yielding good internal consistency (αs ≥ .88).

Post-shooting social support

Post-shooting social support was assessed by the Multidimensional Scale of Perceived Social Support (MSPSS; Zimet, Dahlem, Zimet, & Farley, 1988) at T3. The MSPSS is a 12-item measure assessing perceived adequacy of social support from family, friends, and significant others on a scale from 1 (very strongly disagree) to 7 (very strongly agree). The MSPSS shows acceptable internal consistency, retest reliability, and construct validity (Zimet et al., 1988; Zimet, Powell, Farley, Werkman, & Berkoff, 1990). Mean subscale scores were computed and yielded acceptable internal consistency (αs ≥ .95).

PTSD symptoms

PTSD symptoms were assessed using the Distressing Events Questionnaire (DEQ; Kubany, Leisen, Kaplan, & Kelly, 2000) at T1 and T4. Participants indicated the degree (1 = almost never to 5 = almost always) to which they experienced DSM-IV PTSD symptoms in the last month secondary to a worst-identified trauma. At T1, ratings were in response to an index trauma selected from the TLEQ. At T4, the shooting was the index event. The DEQ has high internal consistency, good short-term reliability, and adequate validity (Kubany, Leisen, et al., 2000). Mean symptom scores were calculated and demonstrated high internal consistencies at both time points (αs ≥ .94).

Depressive symptoms

At T1 and T4, participants rated the degree (0 = did not apply to me at all to 3 = applied to me very much, or most of the time) to which they experienced depressive symptoms in the past week using a subscale of the Depression Anxiety Stress Scale (DASS-21; Lovibond & Lovibond, 1995). The Depression subscale consists of seven items that were averaged to compute a mean depression score. The DASS-21 shows satisfactory convergent validity with similar self-report instruments (Lovibond & Lovibond, 1995). The Depression subscale has also shown high internal consistency in previous research as well as in the present study (αs ≥ .83).

Data Analytic Plan

The main study hypotheses were that social support and negative appraisals would mediate the relationship between T1 trauma exposure (interpersonal trauma vs. non-interpersonal trauma) and psychological adjustment at T4. Study hypotheses were examined using bootstrap analysis in Mplus (Preacher & Hayes, 2008). Bootstrapping is a widely used resampling method that approximates the sampling distributions of population-specific indirect effects. Its confidence intervals (CIs) are percentile-based and are empirically derived rather than assumed to be normally distributed. Bootstrap CIs were bias-corrected, which is an improvement upon the percentile-based bootstrap CIs (Preacher & Hayes, 2008). Mplus also utilizes a robust full-information ML estimation procedure that is a more efficient, less complicated method for data imputation than multiple imputation (Allison, 2012).

Results

Descriptive Analyses

Data were first assessed for quality. Other than age, no other extreme univariate or multivariate outliers were detected. Approximately 16.9% of data were missing at random across variables of interest, as determined by a series of independent t tests (Tabachnick & Fidell, 2007). Bivariate correlations were computed among demographic variables (i.e., age, race/ethnicity, education, T1 PTSD symptoms, T1 depressive symptoms, T2 shooting exposure) and study variables to determine covariate inclusion (see Table 1). Only T1 PTSD symptoms, T1 depressive symptoms, and T2 shooting exposure were significantly related to mediators and outcome variables and were, thus, included as covariates in subsequent analyses.

Table 1.

Means, Standard Deviations, Ranges, and Bivariate Correlations Among Study Variables (N = 515).

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	M	SD	Minimum	Maximum
1. Age	—														18.73	1.18	18	25
2. Education	.76**	—													1.36	0.67	1	4
3. Race/ethnicity	−.05	−.08	—												0.68	0.47	0	1
4. T1 depressive symptoms	<.01	.02	.04	—											1.46	0.47	1	3.43
5. T1 PTSD symptoms	.04	.05	−.01	.48**	—										0.67	0.69	0	3.31
6. T1 trauma exposure^a	−.10*	−.08	.13**	−.22**	−.27**	—									1.47	0.5	1	2
7. T2 shooting exposure	−.13**	−.11**	.04	.07	.13**	−.05	—								2.89	1.68	0	10
8. T3 family support	−.04	−.02	.12*	−.20**	−.17**	.13**	−.06	—							5.83	1.4	1	7
9. T3 friend support	−.04	−.02	.10*	−.17**	−.12*	.07	−.09*	.71**	—						5.9	1.28	1	7.25
10. T3 significant other support	−.01	−.01	.12*	−.12**	−.04	−.01	−.06	.64**	.70**	—					6.02	1.46	1	7
11. T3 self-appraisals	−.04	−.09	.01	.38**	.31**	−.14**	.21**	−.21**	−.24**	−.21**	—				1.71	0.85	1	5.67
12. T3 world-appraisals	−.01	−.01	−.08	.25**	.30**	−.06	.18**	−.17**	−.16**	−.17**	.51**	—			3.54	1.42	1	6.86
13. T4 depressive symptoms	.07	.04	−.08	.35**	.26**	−.17**	.10*	−.20**	−.24**	−.18**	.41**	.25**	—		1.48	0.56	1	3.71
14. T4 PTSD symptoms	.05	.04	−.02	.28**	.32**	−.12*	.27**	−.16**	−.18**	−.13**	.50**	.38**	.43**	—	0.39	0.51	0	2.76

Note. T1 = Time 1; T2 = Time 2; T3 = Time 3; T4 = Time 4; PTSD = posttraumatic stress disorder.

Pre-shooting trauma exposure divided into interpersonal trauma (=1) and non-interpersonal trauma (=2).

p < .05. **p < .01.

Between-Group Differences on Study Variables

Between-group differences on demographic and study variables were examined. As the assumption of homogeneous covariance matrices was violated (Box’s M = 302.73, p < .001), a nonparametric approach was employed. Finch (2005) argued that nonparametric approaches have lower Type I error rates and higher power when covariance matrices are heterogeneous. Group differences were observed for the following variables using Mann–Whitney tests with a Bonferroni-corrected alpha level of .004: T1 PTSD symptoms (U = 19,571.00, p < .001), T1 depressive symptoms (U = 22,544.50,p < .001), T3 family support (U = 20,355.50, p = .001), and T4 depressive symptoms (U = 20,895.50, p < .001). Specifically, prior interpersonal trauma was associated with greater T1 PTSD, T1 depressive, and T4 depressive symptom severity than prior non-interpersonal trauma. Furthermore, participants with prior non-interpersonal trauma reported greater levels of family support than participants with prior interpersonal trauma.

Bootstrap Analyses

A bootstrap analysis examined the indirect effects of T1 trauma exposure on T4 PTSD and T4 depressive symptoms via the hypothesized mediators (i.e., T3 negative appraisals, T3 social support) and adjusting for T1 depressive symptoms, T1 PTSD symptoms, and T2 shooting exposure. Results are shown in Table 2. Contrary to expectation, T1 trauma exposure did not have a direct relationship with T4 PTSD or T4 depressive symptoms. In addition, T1 trauma exposure was unrelated to T3 negative self-appraisals and T3 negative world-appraisals. Prior non-interpersonal trauma predicted increased levels of T3 family and friend support as compared with prior interpersonal trauma. Whereby T3 negative world-appraisals and T3 negative self-appraisals were indicative of increases in T4 PTSD symptoms, only T3 negative self-appraisals were associated with elevated T4 depressive symptoms. No indirect effects were statistically significant at the .05 alpha level.

Table 2.

Mediation Analyses Predicting 12-Month Post-Shooting Outcomes Using Bias-Corrected Standardized and Unstandardized Bootstrap Estimates (N = 515).

Variables	T3 Self-Appraisals			T3 World-Appraisals			T3 Family Support			T3 Friend Support			T3 Significant Other Support			T4 Depressive Symptoms			T4 PTSD Symptoms
Variables	B	95% CI	β	B	95% CI	β	B	95% CI	β	B	95% CI	β	B	95% CI	β	B	95% CI	β	B	95% CI	β
T1 depressive symptoms	0.61	[0.38, 0.85]	0.31	0.52	[0.21, 0.83]	0.17	—	—	—	—	—	—	—	—	—	0.28	[0.13, 0.44]	0.24	0.07	[−0.04, 0.18]	0.06
T1 PTSD symptoms	0.11	[−0.06, 0.27]	0.08	0.43	[0.19, 0.66]	0.20	—	—	—	—	—	—	—	—	—	0.05	[−0.05, 0.15]	0.06	0.13	[0.04, 0.24]	0.17
T1 trauma exposure^a	−0.15	[−0.38, 0.03]	−0.08	0.05	[−0.23, 0.33]	0.02	1.14	[0.82, 1.45]	0.34	0.97	[0.66, 1.27]	0.31	−0.01	[−0.30, 0.27]	<0.01	−0.06	[−0.15. 0.04]	−0.06	0.01	[−0.07, 0.09]	0.01
T2 shooting exposure	0.08	[0.04, 0.13]	0.15	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	0.05	[0.02, 0.08]	0.17
T3 self-appraisals	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	0.15	[0.07, 0.24]	0.25	0.19	[0.09, 0.28]	0.33
T3 world-appraisals	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	0.01	[−0.04, 0.05]	0.02	0.05	[0.01, 0.08]	0.13
T3 family support	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	0.02	[−0.03, 0.07]	0.06	0.02	[−0.03, 0.06]	0.05
T3 friend support	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	−0.02	[−0.08, 0.03]	−0.07	−0.01	[−0.06, 0.03]	−0.04
T3 significant other support	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	−0.04	[−0.09, 0.01]	−0.11	−0.01	[−0.06, 0.02]	−0.03

Note. Estimates and confidence intervals in bold are statistically significant at p < .05. T1 = Time 1; T2 = Time 2; T3 = Time 3; T4 = Time 4. PTSD = posttraumatic stress disorder; CI = confidence interval.

Pre-shooting trauma exposure divided into interpersonal trauma (=1) and non-interpersonal trauma (=2).

Although not included in the initial hypotheses, bootstrap analyses showed significant indirect effects of T1 symptom severity and T2 shooting exposure on T4 symptom outcomes via T3 negative appraisals. Specifically, T1 PTSD symptoms had a significant indirect effect on T4 PTSD via T3 negative world-appraisals (Indirect effect: B = .02, p = .041, 95% CI [0.00, 0.04]). T1 depressive symptoms indirectly influenced T4 PTSD symptoms via T3 negative self-appraisals (Indirect effect: B = .11, p = .006, 95% CI [0.04, 0.20]) and via T3 negative world-appraisals (Indirect effect: B = .02, p = .038, 95% CI [0.01, 0.05]). A similar pattern was observed for T1 depressive symptoms on T4 depressive symptoms (via negative self-appraisals, Indirect effect: B = .09, p = .008, 95% CI [0.04, 0.17]) and T2 shooting exposure on T4 PTSD symptoms (via negative self-appraisals, Indirect effect: B = .02, p = .024, 95% CI [0.01, 0.03]).

Discussion

This study examined the subsequent functioning of trauma-exposed women following a mass campus shooting. It was hypothesized that pre-shooting interpersonal trauma (as compared with non-interpersonal trauma) would be associated with poorer post-shooting adjustment as mediated by post-shooting negative appraisals and levels of post-shooting social support. Present data did not support this hypothesis. Prior trauma exposure was neither directly nor indirectly related to post-shooting PTSD or depressive symptoms. A more reliable predictor of post-shooting adjustment was pre-shooting symptom severity and level of exposure to the shooting and these relationships were mediated by post-shooting negative appraisals. These findings are consistent with research that prior trauma exposure, in the absence of clinically elevated symptoms, may not increase risk for later psychopathology (Breslau & Peterson, 2010; Breslau, Peterson, & Schultz, 2008).

Until recently, prior trauma exposure was recognized as a distinct risk factor for post-trauma sequelae (Bernat, Ronfeldt, Calhoun, & Arias, 1998; Breslau et al., 1999; Brewin et al., 2000; Kilpatrick, Resnick, Saunders, & Best, 1998). Ozer, Best, Lipsey, and Weiss (2008) found that prior trauma exposure yielded a small, yet significant, effect as a risk factor (weighted r = .17). Breslau and colleagues (2008) were the first to find that trauma survivors with a history of PTSD were 2.20 times more likely to develop PTSD symptoms secondary to a subsequent trauma than trauma survivors without a history of PTSD. In addition, the relative risk for later PTSD in trauma survivors without prior PTSD was comparable with individuals without prior trauma exposure. This suggests that prior trauma exposure is only a risk factor if individuals develop subsequent PTSD, which has implications for the sensitization hypothesis. Cougle et al. (2009) countered that risk for PTSD after new trauma exposure, regardless of prior PTSD status, varied as a function of previous trauma type. Their results showed that repeated trauma exposure that included a history of interpersonal violence (with and without prior PTSD) was associated with elevated risk for later PTSD. To the authors’ knowledge, these findings have yet to be replicated in this or other studies (e.g., Breslau & Peterson, 2010). By comparison, depression (with and without trauma exposure) is a consistent predictor of PTSD and comorbid depression following new trauma exposure (Breslau et al., 2008; Shalev et al., 1998). Present findings also demonstrate that the intensity of trauma exposure (as opposed to the type of trauma exposure) may have a greater effect on post-trauma functioning, although further research is warranted.

This study highlighted negative appraisals as an important mechanism for consideration in the sensitization hypothesis. From a cognitive perspective, individuals exposed to potentially traumatic events are at-risk for developing negative appraisals about themselves and others. These appraisals evoke trauma-related symptomatology that, in turn, reinforces these appraisals (e.g., Ehlers & Clark, 2000). Thus, repeated trauma exposure can strengthen preexisting negative appraisals and sensitize individuals to adverse reactions following new trauma exposure. The degree to which appraisals changed following the shooting could not be determined in this study; however, other research shows that the types of negative appraisals reinforced following later trauma may be contingent upon the types of appraisals initially developed following preceding trauma (Littleton et al., 2012). For example, preexisting depression appeared to predict global negative beliefs about one’s self and the world following repeated trauma exposure that was associated with comorbid PTSD and depressive symptoms while individuals with preexisting PTSD seemed to harbor more beliefs about risk of future harm by others that resulted in later PTSD. This study and others have shown that post-shooting negative self-appraisals are a more reliable predictor of subsequent distress than negative world- or self-blame appraisals (Bryant & Guthrie, 2007; Dunmore et al., 2001; Karl et al., 2009). Post-shooting negative self-appraisals predicted both subsequent PTSD and depressive symptoms while post-shooting negative world-appraisals only predicted subsequent PTSD symptoms. Trauma exposure often distorts views of one’s self and can exacerbate pre-trauma negative self-images (Bryant & Guthrie, 2007; Karl et al., 2009).

Contrary to expectation, neither negative appraisals nor social support mediated the relationship between pre-shooting trauma exposure and post-shooting psychological adjustment. The present sample reported relatively few post-shooting negative appraisals regardless of trauma history. It is noteworthy that prior interpersonal trauma was associated with lower perceived post-shooting support from family and friends compared with prior non-interpersonal trauma. One possible explanation may be related to the degree to which social support was perceived as positive or negative following prior traumatic experiences (Andrews, Brewin, & Rose, 2003; Guay et al., 2006; Holeva, Tarrier, & Wells, 2001). For example, women report more negative responses from family and friends following a violent crime than men (Andrews et al., 2003). Consequently, this may decrease their likelihood of calling upon friends and family in the future during times of distress. The null finding for social support as a mediator may reflect precautions taken by the university and larger community to increase emotional support for students, faculty, administrative staff, and community members. The social support received from family, friends, significant others, and the larger community may have mitigated the risks for subsequent PTSD symptoms and other adverse outcomes.

The above findings ran counter to Littleton et al.’s (2012) findings and may reflect important differences between studies. First, the measures used to assess negative appraisals are fundamentally distinct. Littleton et al. (2012) used the World Assumption Scale (WAS; Janoff-Bulman, 1989), which measures current schema adherence. By comparison, the PTCI measures the development of negative beliefs secondary to the trauma (i.e., shooting) and is less appropriate for capturing individuals whose preexisting negative beliefs were reinforced by the shooting. Related to this point, the proximity with which negative appraisals and social support were measured following the shooting could have produced discrepant results. Littleton et al. assessed negative appraisals and social support within two months of the shooting whereas these constructs were not assessed until 6-months post-shooting in this study. Thus, immediate reactions to the shooting may have been more negative and declined over time due to protective factors (e.g., social support). Next, Littleton et al.’s control group was comprised of women with and without trauma exposure, making it difficult to discern whether the experience of sexual assault uniquely resulted in worst post-shooting adjustment. In this study, all participants had a history of trauma exposure, which allowed for differentiating the cumulative effects of different trauma types (i.e., interpersonal vs. non-interpersonal trauma). Finally, the Virginia Tech shooting is one of the deadliest campus shootings to date, resulting in 32 deaths (including the lone gunman) and several others injured. Numerous studies have documented high incidence rates of post-trauma pathology among individuals both directly and indirectly exposed to the shooting (for a review, see Orcutt, Miron, & Seligowski, 2014). Comparatively, subsequent school shootings have involved fewer causalities and injuries (including the present study) and, thus, may have had a lesser impact on the campus and surrounding community relative to the Virginia Tech shooting.

There were other notable limitations to this study. Generalizability of present findings is restricted by gender and race/ethnicity given that all participants were female and predominantly non-Hispanic and White. Consistently, women are found to have higher conditional risk for trauma pathology and sex differences have been attributed to differences in the trauma severity, symptom expression (e.g., aggression vs. distress), strength of negative appraisals, and quality of social support rather than the types of experiences reported (Andrews et al., 2003; Martin et al., 2013; Tolin & Foa, 2006). Thus, men with a cumulative trauma history might have evidenced better post-shooting adjustment than women in this study. Racial/ethnic differences have also been observed for trauma exposure and symptom severity (e.g., Roberts, Gilman, Breslau, Breslau, & Koenen, 2011). Prevalence rates of clinically significant depressive and PTSD symptoms are usually low in college samples (Eisenberg, Gollust, Golberstein, & Hefner, 2007; Elhai et al., 2012). Thus, negative appraisals, social support, and adjustment to the shooting may have varied in a clinical sample.

In light of these limitations, the present study uniquely contributes to extant literature. There are few opportunities to examine individual differences in pre- and post-adjustment to a known traumatic event (e.g., campus shooting). Although it was not feasible to test the sensitization hypothesis directly, study findings show that trauma type appears to have less influence on psychological outcomes following later trauma than preexisting symptom severity and trauma severity. Results also showed that negative appraisals appear to be an important mechanism underlying the cumulative effect of repeated trauma exposure. Specifically, negative self-appraisals were a better predictor of post-shooting adjustment than negative world-appraisals and targeting negative self-perceptions may result in optimal therapeutic gains.

Footnotes

Acknowledgements

We thank all the participants for their continued contribution to the Northern Illinois University Trauma Study and the undergraduate and graduate students who have contributed to data collection.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was funded by grants from the Joyce Foundation, the National Institute for Child and Human Development (1R15HD049907-01A1), and the National Institute of Mental Health (5R21MH085436-02).

Author Biographies

Derrecka M. Boykin, MA, is a doctoral clinical psychology student at Northern Illinois University. Her research primarily focuses on investigating the role of risk and resilience factors underlying individual reactions to trauma exposure, with an emphasis on posttraumatic stress disorder (PTSD) and related conditions. She also has interests in assessing mechanisms underlying treatment seeking, engagement, effectiveness, and outcomes among trauma survivors.

Qweandria T. Dunn, BA, is a former undergraduate research assistant and is currently pursuing a master’s degree in school psychology at National Louis University. Her research interests include social and cognitive adversity due to traumatic experiences, and the impact of abuse and parenting styles on the educational development and mental health issues associated with school-aged children.

Holly K. Orcutt, PhD, is a professor in the psychology department at Northern Illinois University. Her research interests include mechanisms for reducing psychological suffering, particularly following exposure to potentially traumatic events.

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